Clarification plant for physically clarifying sewage



Oct. ,24, 1939. H. P. L. BENDEg.

CLARIFICATION PLANT `FOR PHYSICALLY CLARIFYING SEWAGE Y Filed NOV. 6, .1936

Patented Oct.4 24, 1939 UNITED STATES "PATENT OFFICE cLAaIFrcA'rIoN PLANT Foa rnYsrcAuY CLARIFYING sawaalzv Henry Phil Ludwig Bendel, Paris,-France Application November 6, 1936, Serial No. 1Il9,407

In France November 7, 19,35

12 Claims. (Cl. 210-3) This invention relates to a clarification plant for physically clarifying sewage (including waste water, waste liquor, eiuents) in whichthe sewage with all its suspended matter is sucked oil! ,'15v through vertical immersion pipes out of a supfor operating the new clarification plant are cen# tralised in the middle of the plant.

, In the accompanying drawing a clarification 20 plant according to this invention is shown by way of example.

In the drawing: v Figure 1 shows a section through a clar'ifier which is provided with a submerged hood for catching floating material and a sludge collecting chamber for collecting the sediment material; a. device is also shown for mechanically destroyling by means of water under pressure the floating layer which forms at the surface of the sludge chamber; further it will be seen all the apparatus and ,appliances necessary for operating the plant may be supervised fr'om a central point; and

Figure 2 shows a plan of the plant. The novel features and the mode of operation of the clarifier provided by this invention will be apparent from the following description:

The sewage containing all suspended matter passes through the s upply channel'i into a ldistributing channel 2. The latter is arranged ringshaped at the surface in the middle of the clari,

flcation plant around the servicing chamber 3. From the distributing channel 2 the sewage flows with enhanced velocity through vertical `supply pipes I having a narrow crosssection into the lower part` of the clariiication chamber 5, 6. By this means all the suspended material, that is to say all the floating substances and all the sediment,- are ksucked off together with the sewage into the clarification chamber. At the places where the sewage issues from, the pipes 4 into the clarification chamber 5 there is a great wideningv of the cross section in the clarification chamber. Owing to the suddendlmi'nution in the rate of flow brought about thereby the light floating 55 matter forthwith rises automatically. This matter -collects out of sight in the collecting chamber in a submerged hood 1 of bell shape and is thereby held back from'rising to the surface of the clarication chamber 5, 6.

The heavy sediment immediately deposits on the entrance into the'lower part 5 of the clarification chamber and passes through the ring shaped slit opening 8 into the sludge collecting chamber 9. The sewage freed from the iioating matter and the coarsest sedimentingsubstances then flows slowly in an upward direction to the -overflow I0 arranged in a ring-like manner. Ow-

ing tothe continuously enlarging cross section of flow, the rate of flow during the ascending motion diminishes practically down to zero, with a consequence .that the finest and lightest suspended matter is caused to sediment. This sediment slides downwardly on the steeply inclined side wall of the clarification chamber 5, 6 and, together with the other coarse sediment, passes through the slit opening 8 into th'e sludge chamber 9. The clarified sewage flowingaway over the overflow I Il is collected in a collecting channel II and is either directly led off into receivers,

for example a river, or for biological after-treatment. The floating material collected under the, submerged hood I is periodically let oli under excess water pressure into the centralpump sump I3 after opening one or several valves I2. Into the pump sump I3 the sludge from the sludge collecting chamber 9 is also sent with advantager by way of a vertical sludge pipe I8 and by means of elevated water pressure. This sludge can then be pumped off, together with the floating material let off into the pump sump, into a separate sewage sludge container indicated at 20 for further purification. v

At the surface of the cylinder I4 situated above the sludge collecting chamber 9 and forming the closure with respect to the Iclarification chamber 5, 6 a crust 'or sludge layer I5 forms consisting of ,risen suspended material, which is periodically destroyed by means of water underpressure. The

vwater iet necessary for this destruction is sent on to the floating layer I5 either articially by the sludge pump I6, or by natural descent from a higher sewage sludge container or digestion tank 122. By means of the water jet the substances which form the floating layerV are broken up and 'destroyedso that they` sink through the cylinder I4`back into the sludge collecting chamber 9.

The appliances used for servicing the clarificau tion plan are centralised in the middle inla chamber 3. `All valves, motors and supervision openings are here readily accessible and are com-c bined in a conveniently supervisable form.

In the case of clarication plants `for quantities l tion, instead of one central servicing chamber in the middle of each unit a common servicing chamber may be arranged for all the different units.

The construction and grouping'of the individual parts of the clarification plant according to this invention may for the rest be as desired, and it must be distinctly understood that the accompanylng drawing shows only one constructional form of the invention by way of example.

What I claim is: j

1. In a process for mechanically clarifying sewage containing liquid matter and suspended solid matter which 'tends to rise in said liquid matter, the steps of conducting unclaried sewage to a clarication chamber. at a relatively high veloc'- ity, feeding said sewage into the lower part of said chamber so as to allow said suspended solid matter to rise, intercepting said rising matter in a part of said chamber below the surface of sewage in said chamber, withdrawing intercepted matter from the said part of said chamber and withdrawing clarified sewage from said chamber.

2. In a process for mechanically clarifying sewage containing liquid matter and suspended solid matter which tends to rise tothe surface of said liquid' matter, the steps of conducting unclarifled sewage from a supply channel to a clariilcation lchamber at a relatively high velocity so as to keep said suspended matter mixed with said liquid matter, feeding said sewage into the lower central part of said chamber, owing said liquid matter from said partto a peripheral outlet, at relatively low velocity so as to cause suspended solid unclarifled sewage thru the supply channel of a clarification plant, conducting said sewage from said supply channel to a clarification chamber, at an increased velocity so as to keep said light and heavy suspended matters mixed with said liquid matter in said supply channel, admitting said sewage into a part of said chamber intermediate the top 'and bottom thereof, collectingl said light suspended. matter in another part of.

said chamber, intermediate said first part and the top of said chamber, collecting said heavy suspended vmatter at the bottom of said chamber, collecting the fioating layer formed by said c ollected heavy matter in a separate part of said chamber, withdrawing clarified sewage from said chamber, withdrawing said light collected matter from said other part of said chamber, and removing said heavy suspended matter from said bot-` tom of said chamber.

4. In a vsewage clarification apparatuala supply channel, a clarification chamber, atleast one tube connecting said supply channel with the' lower part of said chamber and including an inlet into the latter, a submerged hood member so disposed in said chamber asA to intercept solids that may tend to rise from said inlet to the level of liquid in said chamber, means to withdraw clarified sewage from said chamber and means to withdraw solidsintercepted by said submerged hood member. v 5. An apparatus as claimed in claim 4 in which the horizontal section of the clarification chamber widens in an upward direction.

6. .An apparatus as claimed in claim 4 in which the clarification chamber has a sludge-*collecting compartment at the bottom thereof and means to withdraw sludge collected in said compart- 7. An apparatus as claimed in claim 4, wherein the end of the supply channel is disposed 'in the upper central part of the clarification chamber,

said connecting tubes connecting said end with the Ilower part of said clarification chamber.

8. An apparatus as claimed in claim 4, wherein 'the end of the supplychannel is disposed in the clarification chamber.

10. An apparatus as claimed in claim 4 having a lsludge-collecting chamber at the bottom of, and opening into, the clarification chamber, means for withdrawingsludge collected in said sludge collecting chamber, a pipe member extending upwardly from the proximity of the bottom of and communicating with, the sludge-collecting chamber, and means for breaking up the floating layer which collects at the surface of the liquid in said pipe member. I

11. An apparatus as claimed in claim 4, including a pipe member extending upwardly in and 'communicating with the clarification chamber,l

and means supported by said pipe member for controlling the discharge of solids intercepted by said hood.

'12. An apparatus as' claimed in claim '4, having asludge-collecting chamber at the bottom of and/opening into the clarification chamber, a pipe member extending upwardly from the proximity of the .opening of the sludge-collecting chamber to the top of the clarification chamber, a distrib- `uting channel connected to the end of the supply channel'and disposed around the pipe member in the upper part of the clarification chamber, and a separate chamber disposed around the pipe .member and substantially extending below said distributing channel; said connecting tube con-- necting said distributing channel to a part of said clarification chamber intermediatethe top and bottom thereof, the hood member being disposed around said separate chamber and adapted .to discharge into the same, means for withdrawing clarified sewage from the top of said clarification chamber, means for withdrawing light collected matter from the said part of said clariiication chamber, and means for removing heavy suspended matter from said sludge-collecting chamber. 

